Research On Trusted Service Mechanism For Crowdsourcing System Based On Blockchain

Crowdsourcing is a distributed problem-solving mechanism and an emerging business model.It is widely used due to its large-scale amateurism and a more equal and open business culture.First of all,in the existing crowdsourcing systems,the requester and the worker are usually required to use the crowdsourcing platform as the trust center,and the payment of fees depends on the third-party central payment institutions.This centralized service mechanism has great security risks.Secondly,in the blockchain-based crowdsourcing system service mechanism designed in this study,due to the open and transparent nature of blockchain,it will bring hidden security risks to crowdsourcing users.Although the use of stealth address protocol can achieve the purpose of privacy protection of the crowdsourcing user's identity information in the transaction,in the currently widely used double key stealth address protocol,some private information of crowdsourcing users will be lost.And there are a lot of time-consuming elliptic curve scalar multiplication operations,which will bring the problem of low service performance of the entire crowdsourcing system;in addition,in the service mechanism of the crowdsourcing system designed in this study,the private key is the only identity proof of the crowdsourcing user,And the wallet program is the tool used to save and manage private keys.Malicious hackers can tamper with crowdsourcing users' wallet program and steal crowdsourcing users' passwords and private keys through malware and virus programs,which will bring extremely high security risks to crowdsourcing users' assets in the entire crowdsourcing system.In view of the above problems,the work of this research is mainly divided into three aspects:(1)Based on the blockchain technology,a new trusted service mechanism for a centerless crowdsourcing system is proposed.This mechanism divides the crowdsourcing service process into nine stages.The execution of each step in eachstage is controlled through smart contracts.The payment of fees is completed by transferring funds within the blockchain without the participation of the third-party central institutions,which will be used to solve the security risks caused by the existence of the central institutions to user assets;(2)Based on bilinear mapping and introducing a local transaction record database,a more efficient duouble-key stealth address protocol with no temporary key leakage is proposed.The sender and receiver each maintain a local transaction record database to record the number of transactions with other users.At each transaction,the sender and receiver generate a temporary key pair for the transaction based on the number of transactions with the corresponding user,so as not to disclose the temporary key of the transaction.The sender calculates the temporary output address of the transaction and the receiver performs verification calculations using bilinear mapping to improve service performance and user privacy security of the crowdsourcing system;(3)Based on trusted computing technology,a trusted protection scheme for secure authentication of wallet and user's private key is proposed.First,the integrity of the wallet program is protected by static and dynamic measurements,and then the user's private key file is sealed and encrypted to prevent malicious stealing of the user's private key to conduct transactions in a heterogeneous environment to achieve the purpose of improving the security performance of the crowdsourcing system.